None.
Not Applicable.
1. Field of the Invention
The invention relates to fluid pumps and controls having valves and switches associated with the pumps for regulating fluid pressure in one or more fluid accommodating structures. More particularly, the invention is directed to air pumps and hand controls for supplying air under pressure to air mattresses and adjusting the pressure of the air in the air mattresses.
2. Related Art
Air beds use air mattresses to provide yieldable body support. The air mattresses are often inflated with pumps, such as hand operated pumps and bag pumps. Motor driven blowers and pumps have also been used to supply air under pressure to air mattresses. The biasing or firmness characteristic of an air mattress is determined by the pressure of the air in the air mattress. The air mattress firmness can be varied by supplying additional air or venting air from the air mattress. Control mechanisms have been used to adjust the inflation of air mattresses. U.S. Pat. Nos. 4,829,616; 4,897,890; 5,509,154 and 5,267,363 disclose different types of inflation devices used with air mattresses.
The invention is drawn to an apparatus for supplying fluid, such as air, under pressure to an air mattress and automatically adjusting the fluid pressure. The apparatus has a coupling device which attaches the apparatus to the air mattress. A housing encloses a motor, an impeller, a two-way valve and a solenoid. The solenoid opens the two-way valve to allow inflation or deflation of the air mattress. The motor is reversible and the impeller is used to force fluid into or out of the mattress. A controller is used to inflate and deflate the mattress. The controller can be attached to the apparatus or it can be a remote control.
A power source supplies the power necessary to operate the motor. The power source can be of any type including AC, DC, or battery. The two-way valve is similar to the valve disclosed in my U.S. patent application Ser. No. 09/909,794 filed on Jul. 20, 2001 (herein incorporated by reference). A display may be used to indicate the pressure in the air mattress as detected by an optional pressure transducer in the apparatus. The pressure transducer can accurately determine the pressure in the air mattress because the two-way valve seals the system. The invention may also include a pressure shut-off switch which is activated at a predetermined pressure. The pressure shut-off switch opens the circuit providing power to the solenoid and the motor. As a result the motor stops operating and the two-way valve is returned to its normally closed position by a biasing spring which pushes the actuator arm of the solenoid away.
In addition to the pressure shut-off switch, there may be a thermal shut-off switch attached to the motor. At a predetermined temperature the thermal shut-off switch is activated with the same results as the pressure shut-off switch.
The coupling device attaches to the air mattress in a number of manners. When the mattress has a threaded opening the coupling device attaches by screwing on to the threaded opening. A resilient o-ring is sandwiched between the opening and the coupling device providing a fluid tight seal. The device can also be used to inflate items without a threaded opening. Different diameter outlets can be selected depending on the application. In the event of a valved closure located on the mattress, the device utilizes an opener extending from the periphery of the outlet.